About 87 people in 35 states have gotten sick from salmonella bacteria, and 27 have been hospitalized.

Yanawut / Getty

It's not clear if all of those cases are due to kratom, which is sold in supplements or as a powder. But investigators asked 55 of the sickened people about it, and 73% said they'd consumed kratom before falling ill. Tests showed 26 different kratom products, from multiple manufacturers, were contaminated.

Kratom is from a tree called Mitragyna speciosa, which grows in Indonesia, Malaysia, Thailand, and other countries. The leaves can be chewed, dried and smoked, or powdered and consumed as a tea or in supplements. It has traditionally been used in those countries to combat fatigue and boost energy, but is promoted in the US as a way to treat muscle pain, diarrhea, and opiate withdrawal. Although it's legal in the US, it's illegal in some Southeast Asian countries.

Kratom is also called Biak, Kakuam, Ketom, Thang, and Thom.

The FDA wasn't happy about kratom even before some of the products were found to be contaminated with salmonella, a type of bacteria that can make people seriously ill. They say there's "strong evidence" that kratom affects the same opioid receptors as morphine, and using it could lead to addiction, abuse, and dependence.

"The FDA continues to warn consumers not to consume any kratom product," the agency said on its site. "There is no FDA-approved use for kratom and the agency has received concerning reports about the safety of kratom, including deaths associated with its use."

At the FDA's request, several kratom-producing manufacturers have voluntarily recalled their products. But one company did not comply.

Eraxion / Getty Images

Artistic rendering of salmonella.

The salmonella outbreak started in February, and in March several companies conducted recalls, including PDX Aromatics of Portland, Oregon (which does business under the names Kraken Kratom, Phytoextractum, and Soul Speciosa); Tamarack of Roy, Utah, and Nutrizone of Houston.

Only certain products have been recalled and are sold under names like Eclipse, Pain Out Thai, Nirvanio Green Malay, White Borneo Powder, Red Maeng Da Capsules, and many more. (Check the links above for specific names and lot numbers.) The products have been sold on the companies' websites and at retailers like Torched Illusions in Tigard and Beaverton, Oregon, and Smoke Station in Salt Lake City.

One company, however, did not recall its products: Triangle Pharmanaturals in Las Vegas. This prompted the FDA to issue a mandatory recall this week, something the agency has never done before. (Yes, that's right. Despite all those "FDA recalls" you might have read about, the federal agency doesn't recall products themselves — they ask manufacturers to do it voluntarily.)

"The FDA is advising consumers to discard the products that are part of the mandatory recall, which include, but are not limited to: Raw Form Organics Maeng Da Kratom Emerald Green, Raw Form Organics Maeng Da Kratom Ivory White, and Raw Form Organics Maeng Da Kratom Ruby Red," the agency said.

Triangle has taken its website offline and could not be reached for comment.

FDA Commissioner Scott Gottlieb tweeted about the recall.

#FDA signed an order to effectuate the first ever mandatory recall, under #FSMA authorities, to address an imminent hazard related to an ongoing outbreak of salmonella associated with a Kratom product. We advise consumers not to consume this product. https://t.co/NMRS1lK6eH

We're guessing the federal agency probably wasn't thrilled to have to take this historic first.

"Our first approach is to encourage voluntary compliance, but when we have a company like this one, which refuses to cooperate, is violating the law and is endangering consumers, we will pursue all avenues of enforcement under our authority,” Gottlieb said in a statement.

Here are some other things you should know.

Every year, about 1.2 million people get sick, 23,000 are hospitalized, and 450 people die from salmonella, according to the Centers for Disease Control and Prevention. You can pick up the bacteria from consuming undercooked poultry, eggs, beef, and unpasteurized milk (or by spreading the germ in the kitchen to foods that aren't cooked, like salad or fruit). Handling reptiles like turtles and other small pets, such as guinea pigs, have been linked to cases. Also, someone who is sick can spread the germ if they handle food.

So salmonella in kratom is a real problem.

"It is within the scope of the FDA to require manufacturers and distributors of dietary supplements to recall products that pose an imminent public health concern or safety issue," Oliver Grundmann, clinical associate professor of medicinal chemistry at the University of Florida in Gainesville, told BuzzFeed News by email. "This is responsible and should be done in the interest of public health and safety."

However, it’s not yet clear if kratom acts on opioid receptors in the same way as morphine or heroin, Grundmann said.

"Isolated receptor studies and computer models can contribute some information but cannot ultimately adequately represent the complexity of a human being,” said Grundmann. This mechanism of action "requires further investigation in clinical studies."

UPDATE

Apr. 04, 2018, at 14:29 PM

The headline and subheadline for this story have been updated for clarity.

Theresa Tamkins is a health editor for BuzzFeed News and is based in New York.